X-Git-Url: http://git.vpit.fr/?p=perl%2Fmodules%2FSub-Op.git;a=blobdiff_plain;f=lib%2FSub%2FOp.pm;h=44b3e9b671d5379b1374f63496e3df64958ed899;hp=94cfe955a538c5d59d7b7b72c8a8e7619570bc9a;hb=159088ccddecdea45fdae8093319b41c097adc86;hpb=a4ea0141e593c7b7afc86b15fb96d7f0ec5ab38a diff --git a/lib/Sub/Op.pm b/lib/Sub/Op.pm index 94cfe95..44b3e9b 100644 --- a/lib/Sub/Op.pm +++ b/lib/Sub/Op.pm @@ -5,17 +5,122 @@ use 5.010; use strict; use warnings; +=head1 NAME + +Sub::Op - Install subroutines as opcodes. + +=head1 VERSION + +Version 0.02 + +=cut + our ($VERSION, @ISA); sub dl_load_flags { 0x01 } BEGIN { - $VERSION = '0.01'; + $VERSION = '0.02'; require DynaLoader; push @ISA, 'DynaLoader'; __PACKAGE__->bootstrap($VERSION); } +=head1 SYNOPSIS + +In your XS file : + + #include "sub_op.h" + + STATIC OP *scalar_util_reftype(pTHX) { + dSP; + dMARK; + SV *sv = POPs; + if (SvMAGICAL(sv)) + mg_get(sv); + if (SvROK(sv)) + PUSHs(sv_reftype(SvRV(sv), 0)); + else + PUSHs(&PL_sv_undef); + RETURN; + } + + MODULE = Scalar::Util::Ops PACKAGE = Scalar::Util::Ops + + BOOT: + { + sub_op_config_t c; + sub_op_init(&c); + c.name = "reftype"; + c.namelen = sizeof("reftype")-1; + c.pp = scalar_util_reftype; + c.check = 0; + c.ud = NULL; + sub_op_register(aTHX_ &c, 0); + } + +In your Perl module file : + + package Scalar::Util::Ops; + + use strict; + use warnings; + + our ($VERSION, @ISA); + + use Sub::Op; # Before loading our own shared library + + BEGIN { + $VERSION = '0.01'; + require DynaLoader; + push @ISA, 'DynaLoader'; + __PACKAGE__->bootstrap($VERSION); + } + + sub import { Sub::Op::enable(reftype => scalar caller) } + + sub unimport { Sub::Op::disable(reftype => scalar caller) } + + 1; + +In your F : + + use ExtUtils::Depends; + + my $ed = ExtUtils::Depends->new('Scalar::Util::Ops' => 'Sub::Op'); + + WriteMakefile( + $ed->get_makefile_vars, + ... + ); + +=head1 DESCRIPTION + +This module provides a C and Perl API for replacing subroutine calls by custom opcodes. +This has two main advantages : + +=over 4 + +=item * + +it gets rid of the overhead of a normal subroutine call ; + +=item * + +there's no symbol table entry defined for the subroutine. + +=back + +Subroutine calls with and without parenthesis are handled. +Ampersand calls are B replaced, and as such will still allow to call a subroutine with same name defined earlier. +This may or may not be considered as a bug, but it gives the same semantics as Perl keywords, so I believe it's reasonable. + +When L and L are loaded, they get automatically monkeypatched so that introspecting modules like L and L still produce a valid output. + +=cut + +use Scalar::Util; + use B::Hooks::EndOfScope; use Variable::Magic 0.08; @@ -38,15 +143,30 @@ my $sw = Variable::Magic::wizard( my $pkg = $data->{pkg}; my $fqn = join '::', $pkg, $name; - _incoming($name, $pkg); - - no strict 'refs'; - *$fqn = $placeholder unless exists &$fqn; + { + local $SIG{__WARN__} = sub { + CORE::warn(@_) unless $_[0] =~ /^Constant subroutine.*redefined/; + } if _constant_sub(do { no strict 'refs'; \&$fqn }); + no strict 'refs'; + no warnings 'redefine'; + *$fqn = $placeholder; + } return; }, ); +sub _tag { + my ($pkg, $name) = @_; + + my $fqn = join '::', $pkg, $name; + + return { + old => _defined_sub($fqn) ? \&$fqn : undef, + proto => prototype($fqn), + }; +} + sub _map { my ($pkg) = @_; @@ -61,8 +181,14 @@ sub _map { sub _cast { my ($pkg, $name) = @_; - no strict 'refs'; - Variable::Magic::cast(%{"${pkg}::"}, $sw, $pkg, { $name => 1 }); + my $map = { $name => _tag(@_) }; + + { + no strict 'refs'; + Variable::Magic::cast(%{"${pkg}::"}, $sw, $pkg, $map); + } + + return $map; } sub _dispell { @@ -72,18 +198,102 @@ sub _dispell { Variable::Magic::dispell(%{"${pkg}::"}, $sw); } +=head1 C API + +=head2 C + +A typedef'd struct that configures how L should handle a given subroutine name. +It has the following members : + +=over 4 + +=item * + +C + +The name of the subroutine you want to replace. +Allowed to be static. + +=item * + +C + +C's length, in bytes. + +=item * + +C + +The pp function that will be called instead of the subroutine. +C is a typedef'd function pointer defined by perl as : + + typedef OP *(*Perl_ppaddr_t)(pTHX); + +=item * + +C + +An optional callback that will be called each time a call to C is replaced. +You can use it to attach extra info to those ops (e.g. with a pointer table) or to perform more optimizations to the optree. +C is a typedef'd function pointer defined by : + + typedef OP *(*sub_op_check_t)(pTHX_ OP *, void *); + +=item * + +C + +An optional user data passed to the C callback. + +=back + +=head2 C + +Initializes the fields of the C object. +For future compatibility, it is required to call this function with your config object before storing your actual values. +It will store safe defaults for members you won't set. + +=head2 C + +Registers a name and its configuration into L. +The caller is responsible for allocating and freeing the C object. +No pointer to it or to its members is kept, except if you pass the flag C in which case the configuration object will be stolen to be stored into L's internal datastructure. + +=head2 C + +Deeply clones the specified C object. + +=head2 C + +Free the memory associated with the specified C object. + +=head1 PERL API + +=head2 C + +Enable the replacement with a custom opcode of calls to the C<$name> subroutine of the C<$pkg> package in the current lexical scope. +A pp callback must have been registered for C<$name> by calling the C function C in the XS section of your module. + +When C<$pkg> is not set, it defaults to the caller package. + +=cut + sub enable { my $name = shift; my $pkg = @_ > 0 ? $_[0] : caller; - my $fqn = "${pkg}::$name"; - my $map = _map($pkg); if (defined $map) { - $map->{$name} = 1; + $map->{$name} = _tag($pkg, $name); } else { - _cast($pkg, $name); + $map = _cast($pkg, $name); + } + + my $proto = $map->{$name}->{proto}; + if (defined $proto) { + no strict 'refs'; + Scalar::Util::set_prototype(\&{"${pkg}::$name"}, undef); } $^H |= 0x00020000; @@ -94,15 +304,38 @@ sub enable { return; } +=head2 C + +Disable the replacement for calls to C<$name> in the package C<$pkg>. + +When C<$pkg> is not set, it defaults to the caller package. + +=cut + sub disable { my $name = shift; my $pkg = @_ > 0 ? $_[0] : caller; - my $fqn = "${pkg}::$name"; - my $map = _map($pkg); + my $fqn = join '::', $pkg, $name; + if (defined $map) { + my $tag = $map->{$name}; + + my $old = $tag->{old}; + if (defined $old) { + no strict 'refs'; + no warnings 'redefine'; + *$fqn = $old; + } + + my $proto = $tag->{proto}; + if (defined $proto) { + no strict 'refs'; + Scalar::Util::set_prototype(\&$fqn, $proto); + } + delete $map->{$name}; unless (keys %$map) { _dispell($pkg); @@ -124,6 +357,18 @@ sub _inject { } } +sub _defined_sub { + my ($fqn) = @_; + my @parts = split /::/, $fqn; + my $name = pop @parts; + my $pkg = ''; + for (@parts) { + $pkg .= $_ . '::'; + return 0 unless do { no strict 'refs'; %$pkg }; + } + return do { no strict 'refs'; defined &{"$pkg$name"} }; +} + { my $injector; BEGIN { @@ -157,15 +402,16 @@ sub _inject { $B_OP_inject{can} = sub { my ($obj, $meth) = @_; if ($meth eq 'first') { - return undef unless defined _custom_name($obj); + return undef unless $obj->isa('B::UNOP') or defined _custom_name($obj); } $obj->SUPER::can($meth); }; - if (%B:: and %B::OP:: and *B::OP::type{CODE}) { + if (_defined_sub('B::OP::type')) { _inject('B::OP', \%B_OP_inject); } else { - Variable::Magic::cast %B::OP::, $injector, 'B::OP', \%B_OP_inject; + no strict 'refs'; + Variable::Magic::cast %{'B::OP::'}, $injector, 'B::OP', \%B_OP_inject; } my $B_Deparse_inject = { @@ -173,12 +419,13 @@ sub _inject { my ($self, $op, $cx) = @_; my $name = _custom_name($op); die 'unhandled custom op' unless defined $name; - if ($op->flags & B::OPf_STACKED()) { + if ($op->flags & do { no strict 'refs'; &{'B::OPf_STACKED'}() }) { my $kid = $op->first; $kid = $kid->first->sibling; # skip ex-list, pushmark my @exprs; - for (; not B::Deparse::null($kid); $kid = $kid->sibling) { + while (not do { no strict 'refs'; &{'B::Deparse::null'}($kid) }) { push @exprs, $self->deparse($kid, 6); + $kid = $kid->sibling; } my $args = join(", ", @exprs); return "$name($args)"; @@ -188,14 +435,73 @@ sub _inject { }, }; - if (%B:: and %B::Deparse:: and *B::Deparse::pp_entersub{CODE}) { + if (_defined_sub('B::Deparse::pp_entersub')) { _inject('B::Deparse', $B_Deparse_inject); } else { - Variable::Magic::cast %B::Deparse::, $injector, 'B::Deparse', $B_Deparse_inject; + no strict 'refs'; + Variable::Magic::cast %{'B::Deparse::'}, $injector, 'B::Deparse', $B_Deparse_inject; } } } BEGIN { _monkeypatch() } +=head1 EXAMPLES + +See the F directory that implements a complete example. + +=head1 CAVEATS + +Preexistent definitions of a sub whose name is handled by L are restored at the end of the lexical scope in which the module is used. +But if you define a sub in the scope of action of L with a name that is currently being replaced, the new declaration will be obliterated at the scope end. + +Function calls without parenthesis inside an C in the scope of the pragma won't be replaced. +I know a few ways of fixing this, but I've not yet decided on which. + +=head1 DEPENDENCIES + +L 5.10. + +L, L. + +L. + +=head1 SEE ALSO + +L. + +L provides a C API to declare XSUBs that effectively call a specific PP function. +Thus, it allows you to write XSUBs with the PP stack conventions used for implementing perl core keywords. +There's no opcode replacement and no parsing hacks. + +L. + +=head1 AUTHOR + +Vincent Pit, C<< >>, L. + +You can contact me by mail or on C (vincent). + +=head1 BUGS + +Please report any bugs or feature requests to C, or through the web interface at L. +I will be notified, and then you'll automatically be notified of progress on your bug as I make changes. + +=head1 SUPPORT + +You can find documentation for this module with the perldoc command. + + perldoc Sub::Op + +Tests code coverage report is available at L. + +=head1 COPYRIGHT & LICENSE + +Copyright 2010 Vincent Pit, all rights reserved. + +This program is free software; you can redistribute it and/or modify it +under the same terms as Perl itself. + +=cut + 1; # End of Sub::Op